It would be great to see support for 64-bit executables, especially on the Linux world.

The current dependency on GTK+ 2.0 32-bit is problematic, as:1) It's not included by default on Linux distros anymore (they use GTK+ 3), as the documentation also mentions.2) On 64-bit Ubuntu-based distros at least, there are issues installing the 32-bit version of GTK+ 2.0, whereas the 64-bit version can be installed rather easily.(e.g. http://ubuntuforums.org/showthread.php?t=2064978)

Considering that almost all the available systems (besides the AmigaOS variants) are 64-bit nowadays, I believe it makes sense to put some effort in adding support for this in Hollywood's compiler.

That's definitely going to come. On Windows and Mac OS X 32-bit apps are not a problem but on Linux it's really quite a hassle to run 32-bit apps so 64-bit support is one of the top priority things now. Unfortunately, this also means having to recompile all plugins for 64-bit because 64-bit apps can't load 32-bit plugins. So it's quite some work.